The knee comprises the joint between the femur and the tibia but also the joint between the patella and the front of the femur. Either or all of these parts of the knee may be affected by arthritis to various degrees. The procedure of joint replacement includes removing the affected joint surfaces and replacing them with metal components with a high-density polyethylene-bearing surface between the metal components.
A total knee replacement is a surgical procedure whereby the diseased knee joint is replaced with artificial material. The knee is a hinge joint which provides motion at the point where the thigh meets the lower leg.
The total procedure takes approximately an hour to hour and a half to perform and recovery time varies between patients. Correct rehabilitation following surgery significantly improves outcomes.
In the total knee replacement procedure, each prosthesis is made up of four parts. The tibial component has two elements and replaces the top of the shin bone (tibia). This prosthesis is made up of a metal tray attached directly to the bone and a plastic spacer that provides the bearing surface.
The femoral component replaces the bottom of the thigh bone (femur). This component also replaces the groove where the patella (kneecap) sits.
The patellar component replaces the surface of the kneecap, which rubs against the femur. The kneecap protects the joint, and the resurfaced patellar button slides smoothly on the front of the joint. This may or may not be replaced depending on the condition of the patient.
Total knee replacement surgery is considered for patients whose knee joints have been damaged by progressive arthritis, trauma, or other rare destructive diseases of the joint.
Regardless of the cause of the damage to the joint, the resulting progressively increasing pain and stiffness and decreasing daily function lead the patient to consider total knee replacement. Decisions regarding whether or when to undergo knee replacement surgery are not easy. Patients should understand the risks as well as the benefits before making these decisions.